Arousal Modulation in Cocaine-Exposed Infants.

Examined arousal regulation as a function of levels of prenatal cocaine exposure in 4-month-olds, using a "still face" procedure. Found that, independent of several other factors, a greater percentage of heavily cocaine-exposed infants, compared to unexposed infants, showed less enjoyment during "en face" play with their mothers and continued to show negative expressions during play resumption following an interruption. (Author)